On Fri, Nov 3, 2017 at 2:20 PM, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote: > There are only a few things the recovery needs to do. Primarily, it just > needs to: > Determine the number of bytes transferred > Get the card back to transfer state > Determine whether to retry > > There are also a couple of additional features: > Reset the card before the last retry > Read one sector at a time > > The legacy code spent much effort analyzing command errors, but commands > fail fast, so it is simpler just to give all command errors the same number > of retries. > > Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> I have nothing against the patch as such. In fact something like this makes a lot of sense (to me). But this just makes mmc_blk_rw_recovery() look really nice. And leaves a very ugly mmc_blk_issue_rw_rq() with the legacy error handling in-tree. The former function isn't even named with some *mq* infix making it clear that the new recovery path only happens in the MQ case. If newcomers read this code in the MMC stack they will just tear their hair, scream and run away. Even faster than before. How are they supposed to know which functions are used on which path? Run ftrace? This illustrates firmly why we need to refactor and/or kill off the old block layer interface *first* then add MQ on top. Yours, Linus Walleij
